1. Field of the Invention (Technical Field)
The present invention relates to multispectral fluorescence signatures for identification of chemical and biological materials.
2. Background Art
Note that the following discussion refers to a number of publications by author(s) and year of publication, and that due to recent publication dates certain publications are not to be considered as prior art vis-a-vis the present invention. Discussion of such publications herein is given for more complete background and is not to be construed as an admission that such publications are prior art for patentability determination purposes.
The use of multispectral signatures along with multivariate analysis has become a viable technique for the identification of chemical and biological materials in mixtures and with strong background signals. In this technique a three-dimensional spectral signature is generated over a predetermined excitation wavelength by measuring the intensity of the resulting fluorescent spectra as a function of fluorescent wavelength that is produced at a number of excitation wavelength. An example of a spectral signature is shown in FIG. 1. The excitation source can be a tunable laser or a continuous light source such as a high-pressure xenon lamp filtered by a monochromator or suitable narrow band filters. The usual method of measurement requires that the excitation wavelength be stepped through a set of wavelengths.
The following references are noted and incorporated herein by reference: H. C. Goicoechea, et al., J. Pharm. Biomed. Anal. 20(1-2):255-61 (1999); H. C. Goicoechea, et al., J. Pharm. Biomed. Anal. 20(4):681-6 (1999); M. L. Luis, et al., J. AOAC Int. 82(5):1054-63 (1999); P. W. Hansen, et al., J. Dairy Sci. 82(7):1351-60 (1999); J. Mendieta, et al., Biophys. J. 74(6):2876-88 (1998); M. E. Ribone, et al., J. Pharm. Biomed. Anal. 23(2-3):591-5 (August 2000); N. R. Martos, et al., J. Pharm. Biomed. Anal. 23(5):837-44 (October 2000); H. C. Goicoechea, et al., Analyst 126(7):1105-12 (July 2001); P. B. Harrington, et al., Anal. Chem. 73(14):3247-56 (July 2001); M. Rhiel, et al., Biotechnol. Bioeng. 5;77(1):73-82 (January 2002); M. Vives, et al., Biopolymers 59(7):477-88 (December 2001); M. S. Collado, et al., Int. J. Pharm. 23;229(1-2):205-11 (October 2001); M. C. Ferraro, et al., J. Pharm. Biomed. Anal. 26(3):443-51 (October 2001); R. Rubenstein, et al., Biochem. Biophys. Res. Commun. 8;246(1):100-6 (1998); J. S. Wagner, et al., Computers in Physics 10(2):114 (1996); U.S. Pat. No. 6,087,182, to Jeng, et al.; and U.S. Pat. No. 5,938,617, to Vo-Dinh.
The present invention provides a method for measuring the spectral signature by simultaneous recording of the fluorescence spectra at all excitation wavelengths.